Spiral for core-molding machines



March 24. 1925,

C. -RABSTEIN s PAIRAL FOR sont: MoLmG MACHINES Fiied Aug. 1s, 1921 orte rires arnrrricn. i

oAsPnnnABsrnrN, or DRESDEN, enniannnnssrenonjro raanznusrnnn, or

' 'y Dnnsnnrnennmnnmfwf v seinen non conn-nonnina Machines;

Application and august 13, leal. serial no. 492,662.

To all whom 'it may concern:

Be it known that l, Casimir. Raes'rnin, mechanician, a subject of the Republic"r of Germany, and resident of' Oberseengasse 8, Dresden, Republic of Saxony, German Republic, have invented a new and useful lmprovenient in Spirals for Core-Molding Machines, for which l tiled applica-tion in Ger-A many Nov. 13, 1916, of which the following is a specification.

lt is well lino-wn to malte use of spirals in connection with core-molding machines, said spirals allowing; to press or squeeze the sand through core-boxeslll/Then using said spirals in the core-molding-machines mentioned, it has been found a great drawback that the spirals are worn or wasted too rapidly. Especially the points of the spirals forming, the parts which are most exposed to wear, are worn very rapidly.

Now the present invention has forits ob ject to obviate the drawback mentioned above. f

llor this purpose the spiral is formed and arranged as follows:

The central-mandrel consists of wroughtiron and is therefore infrangible. rlhe steel windings of the spiral first wound sepa-` rately are hereafter soldered on the central-mandrel by hard-soldering. `When the screw is soldered to the mandrel, the soldering operation will cause the screw and mandrel to become heated, and while the screw is still hot, the latter is exposed to a sudden cooling edect by submerging the screw in cold water, whereby the windings of the screw are rendered glass hard.

The point `of the spiral forming the part exposed to wear in the most intense manner will, in spite of its hardness, nevertheless be subject by and by to wear. ln view of this fact the spiral-point is interchangeable, as is usual with other tools. For this purpose the point of the spiral which is made in precisely the same manner as the other windings, is provided with a thread suitable for screwing it into the central mandrel of the spiral or any other manner suitable for joining it with said mandrel may be used.

The drawing annexed to this description represents an example yof construction of these spirals for` core-molding machines, according` to 'the presentlinvention.

Fig. 1 is a longitudinal elevation and Fie'.

2 a. horizontal section according to lineA-B in 1.

a is the middle or central mandrel onto which the independently wound windings b of steel are' soldered by Vhard-soldering. Forrendering glassdiard saidV steel spiral windings Z), they are rapidly cooled down within the soldering-heat itself. rlhepoint For thispurpose, the spiraltool, provided at its extremity c1 with a thread d to be screwed into a hole c provided at the extremity al of the central mandrel fr for the spiral b. The connection of both parts, viz, the mandrel a and the point c can furthermore be ensured by a pin Instead of a serewconnection any other suitable way of connection may be used.

V What I claim is:

l. A tool for core molding machines, comprising a. mandrel of relatively soft metal and a spiral thread of relatively hard metal secured to said mandrel, the diameter of said thread being progressively diminished toward the end of the mandrel.

2. A tool for core molding machines, comprising a mandrel of relatively soft metal and a spiral thread of relatively hard metal soldered to said mandrel, the diameter of said thread being progressively diminished toward the end of the mandrel;

3. A tool for core molding machines, comprising a tapered mandrel of relatively soft metal and a spiral thread of relatively hard metal secured to said mandrel, the diameter of said thread being progressively diminished toward the end of the mandrel.

4E. A tool for core molding` machines, com prising a tapered mandrel of relatively soft metal and a spiral thread of relatively hard metal soldered to said mandrel, the diameter of said thread being progressively diminished toward the end of the mandrel.

5. A tool for core molding` machines,y com-k prising a tapered mandrel of rela-tively rsoft metal and a spiral thread of relativelyL hard metal secured a distance fromthe` bottom of the mandrelto form a point for'the tool,

the diameter of said thread beingv progressively diminished toward said point.

6. A tool for core molding machines, com

`c of the spiral being' the part of the tool .most eXposed to wear isarranged interchangeable.

point, the windings of which are made in the `*saine manner as the other windings of the i of the mandrel to form a point for the-tool,u the diameter el4 saidy threadY being progres` vprisingg a tapered mandrelv of relatively soft metal and aspirallthread ot relativelyhard metal seldered a distance romithe bottom sively diminished toward said" point. y

7. A. toolfor core moldingmachines, comprising separable members,meansfior coni neeting said members, each of said members being' provided with a fn'ian'drel-oiil'rellative# ly soft metal and a spiral thread oi relatively-71hardA metall secured to ysaid mz'mdrel,

the diameter of said thread being progressively: diminishedA toward* the-end oi' the mandrel. f

S; A tool for Core. molding1machines,eom

f prisii'igfV separable members, means Vfer sein neetin'g said: members, ear'eh 1' olf `said 'members beingilirovidedwith a mandrel-of relativc'ily` soft metal andra spiral thread ot relatively hard/metal.-solderedto sarid mandrel, the di'- ani/etery oiwsaidA tl'ireafd being,`- progressivelyA` diminishedi to'aard the endof the Vmandrel. 9.1 Ai tool* for 'core molding: machines, eompissing 4*se parable:` members, mea-ns yrior eenneeti ng* saidememb ers, Aeach of said-membersl being.' `provided with a\ tapered mandrel? of relatively soit' metal and ra spiralthread of relatively` hard: metal.'` seenredr-y to said mandrel, theldiameter: ol'is gressively diminished toward the end 1ofy the mandrel.l

bers bei ngi previ ded `with i a L tap eredllmandrel 10.A tool for core molding".machines, comprising' separable members', meansl. for eoifmectingrsaid; members, eaehlor said mehr of relatively soft metal a-"vspiialfthread of relatively hairdvmetal soldered to `said mandrel, the" diameter ofi saidithreadfbeing `progfressively diminished toward the end of themandnel L I lifes-tool `for ore molding machines, Compri 115g-separable members, means for bers being' provided with a tapered mandrel oi relatively.' `setti :metal` and a spiral thread ofrelatively hard metal secured to said man- Y drel, the diameter of' said thread being 1pr`of.

gressive'lydiminished toward theend of the mandrel,- onei offsaiid members having-its mandrel eilt-ended to form y 12A; toelffor core molding inaehines,` comprising separable" members, means* for' theiandrel, one 4oit saidmembershavingl mandrel.extended to form a-point belowvsaid threads:

lin testimony, athatl I elaine` the foregoing as 4my invention, Iii-have 'signed my/name iin presence" of tWoF'Witnesses,4` this tvventietl'i da'yro'f July, 1.9.21.

lllitnesses: i f n i L Mi" afNsDrNG, C. SCI-IIEMBAGH. 

